Metal working mechanism



Nov. 10, 1931. R. s. ALLYN 1,830,778

METAL WORKING MECHANISM Original Filed April 26. 1929 2 Sheets-Sheet 1 ix F 13 33 ,1

Ii 49 H 2 41 1 48 I 51 I 25 45 52 55 53 f "I N 46 I 12 I y -47 56 H XlNV OR Robert Allyn,

.BY \fl ATTEY Nov. 10, 1931. R. s. ALLYN Original Filed April 26. 19 2Sheets-Sheet 2 INVENTOR bert S. Allyn, Y

Patented Nov. 10, 1931 UNITED STATES PATENT OFFICE BOBEBJI' S. ALLYN, OFBROOKLYN, NEW YORK, ASSIGNOB T HIMSELF TRUSTEE mar. woaxme mncnamsuOriginal application flied April 26, 1929, Serial Hp. 358,201. Dividedand this application filed September 27, 1930. Serial No. 484,740.

My. invention relates particularly to mechanism for'slitting sheet metalalong rows inclined to the length of the sheets preparatory to expansionin the ni'anufacture of metal laths or fabrics such as shown in theClark Patent 930,350.

U. S. Letters Patent 1,146,554, 1,224,523 and 1,314,507 show variousmechanisms for slitting metal to produce slitted sections alternatingwith unslitted strips or ribs preparatory to its expansion for1nstance-ac cording to methods of the Clark Patents 979.130, 1,052,888,1,104,477 and 1,224,877.

My present invention is intended to provide simple and reliablemechanism for slitting the stock along inclined rows according to thedesired pattern as it is fed through the machine. Mechanisms of thischaracter usually employ stationary dies and go vertically reciprocatingpunch members which are provided with vertical posts, guides or pillarswhich guide the punch and die cutters in their proper relation. It

has been found that in such slitting mechanism there is a substantialhorizontal thrust on the guides. This is believed to be due to thecreeping of the stock caused by the flexing thereof at the shearingpoints away from the cutting edges of the stationary 3o cutters. Thisthrust of course produces friction and wear on the guides and cuttersand also tends to pry the punches away from the dies and drag the stockover theedges of the dies so as to produce irregular and uneven cutswhich make the subsequent expansion very difficult and sometimesimpossible.

I have accordingly rearranged the punch and die cutters so as in effectto balance the horizontal shearing stresses not only laterally of thedirection of feed but longitudinally as well and thus relieve theguide-pillars or posts of the friction heretofore due to the shearingaction. By such means it is possible to increase the speed, reduce thewear on the guides as well as on the cutters, prevent vibration andproduce a more uniform product. As an incident more or less 50 to thesefeatures the cutters may have a longor life. This of course reduces thecost of the cutters for a given output.

It, also reduces the labor of replacement and adjustment and makes itpossible to keep the slitting machine in operation a greater length oftime.

To effect this balanced shearing stress the cutters are arranged so thatone half of the punches cut the strands downwardly in front of thecoacting dies and one half of the punches cut the strands in rear of therespective coacting dies, thus balancing the thrusts longitudinally. Onehalf of the punches cut the strands downwardly to the right of theirdies and one half out their strands to the left thus balancing thethrusts laterally. As part of the strands are thus formed behind thedies it is necessary to lift them over the dies in order to permitfeeding. I therefore flatten or crush these strands somewhat, preferablyby means of spring pressed strippers, so as to ensure more uniformslitting. By properly bending the strands or the ribs or both strandsand ribs the stock may be expanded subsequently in various ways.

Fig. 1 is a longitudinal sectional view of one form of mechanismembodying my invention.

Fig. 2 is a plan view and section of the dies and punches speciallyarranged for balanced shear.

Fig. 3 is a plan View and section showing another modification in whichplate cutters are arranged to produce a balanced shear.

Fig. 4 is a fragmentary detail showin one pattern of slitted stock.

Fig. 5 is a front view of a fragment of feedout rolls.

The stock is fed into the machine intermittently by rolls 1010' and fedout intermittently by the rolls 11-11'. The'die holder 12 is suitablymounted in the machine and the punch holder .13 is guided on the postsand pillars 14: and actuated intermittently in the usual manner. It willbe understood of course that the feed of the rolls may be adjusted tocontrol the widths of the strands in the usual manner and that thestroke of the punch may also be adjusted. in any usual manner.

A typical slitting pattern is shown in Fig. 4, where there are unslittedmarginal and interior main strips or ribs 15'15' and unslittedintermediate strips or ribs 16 -16' which may be narrower. The sections17 and 18 are slitted along lines inclined in opposite directions. Eachslitted section is com osed of inclined strands l919 connected by onds20. The slits 21 are formed b the intermittent action of the cutters ast e stock is fed through the machine.

As set forth in the Clark patents the cutters may be either wedge shapedwith cutting edges on their opposite faces or in the form of plates heldin position by wedges or inclined blocks. In the form shown in Figs. 1and 2 the punch and die cutters are arranged in two rows spaced apartfrom each other longitudinally. The die cutters 25--25 in the rear roware wedge shaped, located in a groove 26 and individually clamped orheld 1n place by screws 27. Wedge shaped blocks such as 28 and 29 may beemployed to assist in holding the cutter blocks laterally and set screws30 may be provided to apply lateral pressure. The punch cutters for thisrow consist of pairs of plates 31 and 32 held in lace in the-punchholder by means of spaced locks 33. clamp screws 34 or other suitablemeans. The co-operating edges of the punch and die cutters are providedwith notches such as 35 so that each punch plate and the correspondingcoacting cutting edge of a die block will form three short slits leavingbonds 20 as above setforth.

The die .cutters in the front row consist of plates such as 36 and 37similar to the punch plates 31 and 32 and are held ina transverse groove38 by means of blocks. 39 and 40 and clamps and set screws similar tothose above described. The co-operating punch cutters 41 are similar tothe wedge shaped die cutters 25 andare held in place by set screws suchas 42 and so forth.

Each punch cutter 31 shears the stock downwardly in front of and to theright of the coacting cutting edge of the wedge shaped die cutter 25.Punch cutter 32 shears stock in front of and to the left of the diecutter 25. The transverse shearing stresses are thus balanced in eachunit of the rear set of cutters as the reverse-lay of strands is out inthe sections 17 and 18. There is, however, an unbalanced forward thruston the pillars or guides 14 as the punches slip forwardly over the edgesof the dies.

In a similar manner the shearing units in the front row are individuallybalanced transversely but produce arearward unbalanced thrust since thepunch cutters cut strands downwardly and to the rear of the ilges informing the slitted sections 17' and Each shearing unit in the front rowtherefore provides a rearward thrust longitudinally' of the feed tocounterbalance an equal but opposite forward thrust .from a-siinllarunit in the rear row.

In orde'rto prevent the stock from sticking to the punch and die cuttersI provide suitable stripping plates as shown in Fig. 1. The

strippingplate 45 is su ported on springs 46 and adjusting studs 4 andprovided with suitable passages for the die cutters. This plate is.adjusted to a height slightly above the up er face of the die cuttersand is ada t- 7 ed to e de ressed when the punch mem r impacts againstit. The upper stripper late 48 carried .by the unch member is sim' arlypressed downwar ly by springs 49 and provided with adjusting studs 50 sothat its lower face may normally be slightly below the lower face of thepunch cutters.

The front and rear edges of the die stripper 45 are preferably providedwith introductory and delivery guide portions 51 and 52, hinged to thestripper '45 at 53 and 54 and provided with guide pins 55,. 56 so thatas the main bod of the stripper plate is ad-' justed up and own tocorrespond with the height of the die cutters, the edges of the guideplates near the feed rolls will remain substantially on a level with thesheet which is fed through the rolls 10-10 and delivered to the rolls11--11'.

By suitably shaping and adjusting the upper and lower stripper platesthey may be made to bear on the slitted stock after each stroke of thepress so as to somewhat crush or flatten the strands as they are formed.The lower or die stripper plate 45 is especially essential beneath thosepunch cutters which draw the stock down in rear of the dies, forinstance beneath the punch cutters 41, since it is necessary to lift thestrands thus formed up sufliciently to clear the faces of the dies 36and 37. It is also quite desirable that the punch stripper 48 engagethese depressed strands at the next slitting stroke so as to steady themwhile the next row of slits is being formed.

It will be understood of course that the length of the cutting edges ofthe punch and die members and the spacing of the shearing units will bedesigned to produce the desired length and number of strands and thedesired width of unslitted strips or ribs.

When it is desired to give special inclination to the strands or ribsthe feeding out rolls 1111' may be provided with specially shapedconical portions, such as 60-61, for 1 arranged in two rows spaced apartfrom each other in the direction of the feed. In the rear row the diecutters 70--70 are inclined opposite to the die cutters 7171. The punchoutters 7 2-7 2 and 7 3-7 3 are arranged to coact with the die cutters70 and 71 respectively so clined and arranged to produce a laterallybalanced shear and a longitudinally unbalanced shear which offsets theunbalanced longitudinal shear produced by the rear row of cutters.

The central space 78 between the right and left hand sets of cutters isslightly wider than V the area slitted by the two centralplates orcutters in the rear row. The cutters in the rear row are lined u withthe spaces between the cutters in the .ront row so as to leave thenecessary unslit-ted strips to form the ribs of the fabric after it isexpanded.

It will be seen that in this form there are just as many shearing unitsin the front row as in the rear row so that the horizontal thrusts arefully balanced leaving the posts 14 to act as guides with a minimum offriction.

There are four groups or sets of punch and die cutters, 1. e., first-thecutters 7270 which shear strands to the right and rear of the diecutters 70, secondthe cut.ers 73-71 which shear strands to the left andrear of the die cutters 71, thirdthe cutters 7674 which shear strands tothe right and forwardly of the die cutters 74, and fourth the cutters 77-7 5 which shear strands to the left and forwardly of the die cutters75.

In the form shown in Fig. 2, the left hand edges of the punch cutters 41and the right hand edges of die cutters 37 correspond with the firstgroup, the right hand edges of cutters 41 and the left hand edges of thecutters 36 correspond with the second group, cutters 31 and 25correspond with the third group and cutters 32 and 25 correspond withthe fourth group. Each row of cutters thus contains two groups whichbalance each other laterally and the cutters of each row balance orapproximately balance the cutters 0f the other row. There is thereforeno substantial thrust on the guide posts due to unbalanced horizontalshearing stresses.

This application is a division from 358,201 filed April 26, 1929, nowPatent 1,781,533 dated Nov. 11, 1930.

I claim:

1. In a metal slitter, means for feeding a sheet, two rows of diecutters having their cutting edges inclined with respect to thedirection of feed, some of the cutters in each row being inclined in theopposite direction to the remainder of the cutters in the same row, thecutters at the o posite sides of the center line in one row be ngparallel respectively to the cutters at the opposite sides of the centerline in the other row and punch cutters coacting with the respecive diecutters, some of the unch cutters being arranged to cut stran s in frontof the coacting die cutters and other punch cutters being arranged tocut strands in rear of the corresponding die cutters.

2. In a metal slitter, means for feeding a sheet forwardly, and coactingpunch and die cutters arranged in two parallel rows extendingtransversely of the direction of feed for forming reversely slittedstrand sections, all the cutting edges being inclined relative to thedirection of feed, one half of the cutting edges being inclined towardthe right and the other half being inclined toward the left, one half ofthe punch cutters cutting to the ri ht of the coacting die cutters andthe other alf of the punch cutters cutting to the. left of the coactingdie cutters.

3. In a machine for slitting sheet metal, means for feeding sheets in acertain direction, and a number of pairs of coacting punch and diecutters arranged in spaced rows with their cutting edges inclined to thedirection of feed, some cutters being inclined in the opposite directionto others, some of the punch cutters cutting the stock in front of thecorresponding die cutters and others of the punch cutters cut ing thestock in rear of the coacting die cutters, some of the punch cutterscutting the stock off the right hand sides of the coacting die cuttersand others of the punch cutters cutting the stock off the left handsides of the coacting die cutters.

4. In a metal slitter, feeding means, parallel spaced rows of diecutters having their cutting edges inclined with respect to thedirection of feed, half of the cutters in each row being inclined in theopposite direction to the remainder of the cutters in the same so a row,the cutters at one side of the center line in each row being parallel tothe cutters at the opposite side of the center line in the other row andpunch cutters coacting with the respective die cutters.

5. Slitting mechanism comprising punch and die members having coactingcutters arranged in two rows extending transversely of the direction offeed of the stock, means for feeding the stock between the punch and diemembers, guides for maintaining the punch member in its proper relationto the die member, the die cutters in one row being in Wedge shape formwith cutting edges inclined relative to the direction of feed of thestock, punch cutters in the other row being of wedge shape with cuttingedges inclined to the direction of feed.

6. Slitting mechanism comprising punch '4 I .8mm

. and die holders each having two transverse grooves, one in front ofthe other, 'de members for the punch holder, means or feeding stockbetween the punch and die holders, two 5 rows of punch and diecuttersmounted respectively in the grooves of the punch and die holders andarranged transversel of the direction of feed, one row being in ront ofthe other, the cutters in each row being arranged in pairs spaced apartfrom each other laterally, all of the cutters bein inclined with respectto the direction of fee and one cutter of each pair being inclined inthe direc-' tion opposite to the other cutter of said pair so as toproduce a reverse lay pattern of slitting.

7. Slittin mechanism comprising punch and die mem ers having cuttinedges spaced and inclined to form. incline strands con- 10 nected bylongitudinal unslitted stri s, said punch and die members being arrangein two 'rows extending transversely of the direction of feed and spacedapart from each other, a

.reciprocable cross head carrying the punch 2 members, a springsupported stripper plate having openings for the die members, a springpressed stripper plate actuated by the cross head and having openingsfor the punch members, a guide plate having one end movable up and downwith the 5 ring supported stripper plate, means for eed1ng stock to saidguide late and means for maintaining one edge 0 the guide plate at theapproximate level of the feeding means.

8. Slitting mechanism com rising unch and die holders, means for fee ingstoc lon- 'gitudinally between said holders, guides for the punch holderand two rows of punch and die cutters arranged transversely in theholdersand all inclined with respect to the direction of feed of thestock, approximately onehalf of the cutting edges being inclined in onedirection and approxlmately one-half of the cutting edges being inclinedin an opposite direction with respect to the directlon of feed, some ofthe unch cutters being arranged to cut stock orwardly of the coactingdie cutters and others of the punch cutters being arranged to cut stockrearwardly of the coacting die cutters.

ROBERT S. ALLYN.

